Adolescence is a time of dramatic biological, behavioral and social changes. It is one of the healthiest periods of the life-span, yet morbidity and mortality rates increase 200%, often attributed to natural tendencies to explore and take risks that increase vulnerability to risky and dangerous behaviors. Rapid advances in developmental neuroscience are revealing new insights into how biology and social context interact to increase adolescents' risk-taking behavior which is attributed to a temporal disassociation between maturational changes in two distinct neural systems: ?socio-emotional? (reward) and ?cognitive-control? (self-regulation). The socio-emotional system is stimulated by a rapid increase in dopaminergic activity at puberty, which influences reward-seeking behavior. This increase in reward-seeking precedes the maturation of the cognitive-control system and its connections to the reward system. This proposal aims to apply these new insights on neurobiology of adolescents' responses to alcohol/drug use and sex-related risk opportunities by examining brain changes in response to a theoretically- based and empirically-tested prevention program that targets risky behavior in African-American youth during pubertal transition. This racial group is disproportionately affected by the high morbidity and mortality associated with HIV-related risky behaviors and exemplifies a significant health disparity in our society. The intervention was designed on the basis of developmental issues and socio-cultural contextual processes germane to African- American families, and has been shown in randomized controlled trials to delay/deter HIV-related risky behaviors in this vulnerable population. This proposal extends the efficacy studies of the intervention by using functional magnetic resonance imaging to quantify the biological changes in response to the intervention. Identifying neural substrates of the intervention can facilitate refinement of the program by focusing on the components that are most effective in changing behavioral and neural circuitry and also aid in the development of new interventions for subgroups of youth that don't have a positive outcome. Using a randomized controlled design, we will assess the neural substrates of risk-taking and risk-avoidant behavior before and after the 6-week computer-interactive, family-based intervention in 11-13 year-old African-American youth. Psychological processes shown to mediate the intervention effects on behaviors that dissuade alcohol and drug use and sexual onset (i.e. reward-drive and cognitive-emotional self-regulation) will be assessed at baseline and 3 months post-intervention. Based on prior studies that reported observable brain changes in response to psychosocial interventions, our hypothesis is that a positive response to the intervention will be associated with greater functional connectivity changes between the socio-emotional (reward-drive) and cognitive-control (self-regulation) components of the neural circuitry compared to the control condition, both at rest and during task-performance. We also postulate that these neural changes will mediate the intervention's positive effects on psychological processes involved in youth's decision to avoid HIV-risk vulnerability behaviors in the service of long-term personal goals and positive health outcomes.